Seeing dead flies makes other flies die faster, but why?

When dead flies lie on a windowsill, it can have an effect on the lives of their congeners. Studies have shown that fruit flies of the Drosophila melanogaster species that see the corpses of their dead friends live significantly shorter lives. They begin to behave withdrawn, lose fat deposits, and their aging is accelerated to the point where they die earlier than fruit flies that do not see their dead buddies.

Scientists have recently figured out why this happens. Two types of neurons receptive to the neurotransmitter serotonin are activated when fruit flies perceive their dead mates, and this increased activity accelerates the flies’ aging process.

Sensory processes can affect aging, but we are not particularly aware of how this happens. The group’s previous study exhaustively demonstrated that perception of dead flies of the same species, known as congeners, has a marked effect on fruit flies, showing that they wither and die early, but the reasons for this were unknown.

In fruit flies, the changes appear to be related to serotonin, an important neurotransmitter that transmits signals between nerve cells, and one of the serotonin receptors, 5-HT2A. The researchers began here by investigating which neurons expressing 5-HT2A might be involved in the physical effects of what the researchers call “death perception.”

What the researchers say

“Understanding the neural circuits through which death perception affects these phenotypes may inform future work aimed at understanding the consequences associated with this and possibly other sensory experiences in humans, including humans, and may provide insight into how specific neural states affect behavior and physiology. – writes a team of researchers led by physiologists Christy Gendron and Touhin Chakraborty of the University of Michigan.

There’s not much we can do with this information yet. The fly brain is very different from the human brain, but the team hopes that one day it will help us better understand how our brains work and the aging process, especially in people who play complex roles in society.

Interesting Facts

– Necrophoresis, or removal of dead congeners, in eusocial insects, vocalization and cadaver inspection in elephants, or increased levels of regulatory hormones called glucocorticoids in nonhuman primates, can also affect animal life.

– The researchers injected live flies with fluorescent protein and showed them dead congeners to observe which parts of the live flies’ brains lit up as they watched the carcasses.

– Scientists hope this information will help better understand how our brains work and the aging process, especially in people who play complex roles in society.